Multicasting is a well known method of transmitting messages to selected groups of users across a network, such as the Internet. One simple example of multicasting involves transmitting an E-mail message to a plurality of users that each are on a mailing list. Video conferencing and teleconferencing also use multicasting principles and, consequently, often are referred to as “multiconferencing.”
To enable users of a computer network to establish a multicast, the network devices (e.g., routers or personal computers) associated with each user of a multicast must be logical and/or physically connected. To that end, users in a multicast are logically connected through a structure known in the art as a “multicasting tree” (also referred to as a “multicast tree” or “tree structure”). Network management and multicasting applications use the multicast tree for a number of purposes, such as for routing data in the multicast and troubleshooting multicast problems.
A number of different multicasting protocols have been developed to implement multicasting within a network. Among others, those protocols include the Protocol Independent Multicast (“PIM”) and the Distance Vector Multicast Routing protocol (“DVMRP”). Like other such protocols, both PIM and DVMRP each build a multicast tree in accordance with processes that are defined specifically for such protocols. Information about such trees is stored in databases that are accessible to those specific protocols only. Accordingly, by way of example, a database with tree information for PIM cannot be read by an application used for DVMRP.
There are times, however, when applications that are configured for use with one multicast protocol must read tree information stored in a multicast database that is configured in another format. In such case, the multicast database cannot be read and thus, no such tree information can be recovered.